Driving mechanism for the weft inserters of shuttleless looms



Nov. 25, 1969 A. c. MONGE 3,480,046

DRIVING MECHANISM FOR THE WEF'I INSERTERS OF SHUTTLELESS LOOMS Filed Jan. 29, 1968 2 Sheets-Sheet 1 29 2a 30 /7 4 L/ x Nov. 25, 1969 A. c. MONGE 3,480,046

DRIVING MECHANISM FOR THE WEFT INSERTERS OF SHUTTLELESS LOOMS Filed Jan. 29, 1968 2 Sheets-Sheet 2 United States Patent Int. Cl. D03d 47/00 U.S. Cl. 139-122 2 Claims ABSTRACT OF THE DISCLOSURE The weft inserter is carried for rectilinear reciprocating movement by a carrier member which slides on a bar. From the same bar, rotatable pulleys are suspended by means of forks arranged at either side of the carrier member. The pulleys carry an endless belt to one run of which the carrier member is fixedly attached. The entire pulley-belt system is reciprocated. During the reciprocating movement, the other run of the belt is held at a fixed point so that the belt moves with respect to the moving system and the weft inserter travels in a rectilinear path double the length of the travel of the system.

This invention relates to a system for operating weft thread inserters in shuttle-less looms of the type comprising a rigid rectilinear weft inserter, weft thread gripping means provided at one end of the inserter, and means for transmitting the drive to said elements.

Various systems are known for the insertion of weft threads through the shed to form a fabric in shuttle-less looms, including movements which drive a rigid inserter on whose extremity is mounted a pincer or hook to hold the warp thread. Other systems consist of pulleys mounted on one side of the loom, which drive a flexible strip or tape having holes which are engaged by pins set in the tire of the pulley, the said pulley rotating to insert the strip or tape into the shed and withdraw it. There is also a variation of the latter system, in which, instead of a single drive pulley, one pulley is mounted at each side of the loom, each driving one flexible or rigid inserter,

and both meeting in the center of the shed to transfer the weft thread from one inserter to the other on their passage through the shed.

All these mechanisms have the drawback that they are excessively bulky, very heavy and expensive, and they produce vibrations in the operation of the loom. Furthermore, in most of the known systems, the weft thread is caught by the inserter without coming to a complete stop, which causes shock loads on the thread and thread breakage. Likewise, the weft thread is cut in these systems while it is in movement, resulting in poor finish at the edges of the fabric.

According to the invention, all these objections are overcome, by improvements which make it possible to use kinematic means or any movement transmitting means for driving the weft thread inserter, while reducing the size of said means to at least half of that used hitherto to produce the movement of the weft thread inserter, both as regards the height and as regards the depth of said driving means, but without reducing at all the useful length of the stroke of the weft thread inserter; in other words, any driving member that has been used for this purpose hitherto will have its original stroke length multiplied by two if the improvements of the invention are applied to it.

The device according to the invention comprises two pulleys of equal diameter situated in the same plane and disposed to rotate freely on individual shafts supported by 3,480,046 Patented Nov. 25, 1969 two forks, one at each extremity of a supporting bar, whereby the said pulleys are connected to one another by an endless belt. This assembly is given a reciprocating rectilinear movement which is produced by any known kinematic system or movement transmitting system, and one section of the endless belt is attached at a point between the two pulleys to a movable element which can slide along a stationary guiding bar and which bears the rigid rectilinear weft thread inserter, while the other section of the endless belt is attached to a fixed point. The assembly of the pulleys and the bar supporting the same is supported by the same guiding bar that carries the movable element which bears the rigid rectilinear weft thread inserter, being attached thereto by means of brackets capable of sliding along said guiding bar. Due to the fact that the endless belt is attached to the fixed point, and due to the displacement of the entire assembly consisting of the two pulleys supported on their bar, said movable element which bears the rigid rectilinear weft thread inserter performs a twofold travel along its guide bar, driving the weft inserter and making it perform a reciprocating movement of double length.

The fixed point to which the endless belt is attached is constituted by a member that is capable of being displaced over a short distance along a second stationary guiding bar by the action of a connecting rod controlled by a cam, for the purpose of momentarily counteracting the displacement of the movable element bearing the rigid rectilinear weft thread inserter, and hence counteracting the displacement of this same inserter, keeping it in a static position for a short period of time at the end of its travel; this allows of gripping the weft thread and cutting it according to a precise pre-arranged schedule.

For the better understanding of the invention it is described in greater detail hereinafter, with reference to the attached drawings which illustrate by way of example a preferred embodiment. In the drawings:

FIG. 1 is a diagrammatic front elevation of the stroke length multiplying device of the weft thread inserter in shuttle-less looms, in the position of the commencement of its movement through the shed;

FIG. 2 is a diagrammatic front elevation of the same device showing the weft thread inserter advanced to half of its travel through the shed;

FIG. 3 is a diagrammatic front elevation of the Same device showing the inserter at the end of its travel through the shed to pick up the weft thread, the broken lines representing the position for the counteraction of the weft thread inserted travel so as to keep it in a static position for a brief period of time during the picking up of the weft thread; and

FIG. 4 is a diagrammatic front elevation of the device embodying the invention, shown assembled to a shuttleless loom, only fragmentary parts of the loom being illustrated.

In these drawings, 1 represents the rectilinear inserter of the weft thread, 2 the guiding bar supported at points 3 and 4 on which the movable element 5 slides which bears the weft thread inserter 1; said movable element 5 is attached to the belt 6 at point A. Belt 6 runs between pulleys 8 and 9 of equal diameter, which rotate on the shafts 10 and 11 which are supported by forks 12 and 13 mounted on the ends of the supporting bar 14; pulleys 8 and 9 and belt 6 are kept under tension by the tension spring 15 arranged on the supporting bar 14. The entire assembly is slidingly supported on guiding bar 2 by means of brackets 16 and 17.

Point A on the lower run d of belt 6 is equidistant from point A on the upper run e; at said point A, the belt 6 is attached to a block 7 slidingly supported on a short guiding bar 18 which in turn is supported at fixed points 19 and 20; the block 7 is also pivotally connected to the rod 21, which is in turn pivotally connected to the end 22 of a crank 23 which pivots at its other end 24 at a fixed point 25 and is in contact with a cam 26 revolving on a shaft 27. i

In FIG. 4 there are illustrated at 33 frame portions of the loom, at 34 and 35 frame portions of the loom heads and at 36 frame portions of the movement transmission means. As illustrated, these movement transmission means comprise a driving motor 37, a transmission belt 38, a driven pulley 39 and a well known hypocycloidal gear mechanism 40, through which the rotating movement of pulley 39 is transmitted as a rectilinear reciprocating movement to the shaft 10 of pulley 8.

The operation of the device is as follows:

Any driving means applied to the shaft 11 of pulley 9 or to the shaft 10 of pulley 8 as illustrated in FIG. 4, will drive the entire assembly formed by the supporting bar 14 and pulleys 8 and 9 in a reciprocating movement, and as a result the supporting bar 14 is horizontally displaced in the direction of the arrow B, as seen in FIG. 1. When the movement of the entire assembly begins in the direction of the arrow B, the inserter 1 also begins to pick up the weft thread 32, since belt 6 is attached at point A; pulleys 8 and 9 rotate, and belt 6 runs in the direction of the arrows B, pulling the movable element and inserter 1 with it in the same direction as the entire assembly. This operation continues in the direction of arrow B to the midpoint of the travel of inserter 1 through the shed 28 formed by the upper threads 29 and lower threads 30 of the warp, which is shown in FIG. 2. This figure clearly shows that, with a travel amounting to no more than the length a on the part of the assembly of supporting bar 14 and pulleys 8 and 9, a travel path of the movable element 5 and consequently of inserter 1 has been produced, which amounts to the distance 2a.

The inserter 1 continues on its Way through the shed 28 formed by upper threads 29 and lower threads 30 of the warp, until the fully extended position of inserter 1, as shown in FIG. 3, is reached, in which it has covered the full length of its travel. This total travel length 4a has then been obtained by a displacement 2a of the assembly of supporting bar 14 and pulleys 8 and 9, i.e. the length of travel of inserter 1 is twice as long as the length of travel of the assembly of supporting bar 14 and pulleys 8 and 9.

Even though the reversing of the travel of inserter 1 produces an instantaneous stop for the picking up of the weft thread 32 at the instant of the change in the direction of the reciprocating movement, the motion of this invention make it possible to prolong this stop to permit the weft thread to be properly caught and effectively severed, thus entirely eliminating failures in the picking up and cutting of the thread.

This is achieved by means of a small displacement of belt 6 from point A to point A", as represented in broken lines in FIG. 3. This displacement, and the displacement of the sliding block 7 on the small guiding bar 18, is

brought about by the revolving of cam 26 in the direction of the arrow C, which pivots crank 23 on its bearing 25, and in turn moves the rod 21 connected to the crank 23 at point 22 and to the sliding block 7 at point 31; this displacement of the lower section at of belt 6 in the same direction as the assembly of supporting bar 14 and pulleys 8 and 9 results in a reverse displacement of the same amplitude in the upper section e of belt 6, i.e. in a movement contrary to the displacement of the assembly of supporting bar 14 and pulleys 8 and 9, which counteracts the travel of movable element 5 for the purpose of controlling the length of stroke of weft thread inserter 1 and producing a momentary standstill of movable element 5 and consequently of the weft thread inserter 1 for the short period of time needed to gri the weft thread 32 and sever it, as set forth above.

The constructional details and features employed in the reduction to practice of the invention are independent of the subject of the same. In particular, the endless belt 6 can be replaced by an endless chain or the equivalent, all this being comprised within the scope of the following claims.

I claim:

1. A driving mechanism for straight weft inserters of shuttleless looms comprising a supporting bar, a belt drive arrangement slidably supported on said bar, means imparting to said belt drive arrangement a rectilinear reciprocating movement, said belt drive arrangement including two holders slidably mounted on said bar, shafts supported by said holders, pulleys of equal diameter rotatably mounted on said shafts and situated in the same plane, and an endless belt connecting said pulleys; means carrying said weft inserter, said carrier means being slidably mounted on said bar and fixedly connected between said pulleys to one run of said endless belt; means holding the other run of said endless belt so as to produce a movement of the belt and displacement of said slidable carrier means in addition to the displacement of said carrier means in addition to the displacement of the entire belt drive arrangement and to impart to the weft insertor a corresponding rectilinear reciprocating movement.

2. A mechanism as claimed in claim 1 wherein said holding means comprise a second stationary bar, a member fixedly attached to said other run of the belt and slidably mounted on said second bar, means actuating said member, and a cam cooperating with said actuating means to impart to said member and said belt, at the end of the stroke of the weft inserter, a transistory movement in the direction opposite the direction of movement of the belt drive arrangement, so as to hold the weft inserter carrying means with the weft inserter for a short time in a stationary position.

References Cited UNITED STATES PATENTS 2,066,532 1/1937 Kellogg et a1 139-123 3,335,760 8/1967 Schetfel 139122 HENRY S. JAUDON, Primary Examiner 

